diff --git a/Simulation/CMakeLists.txt b/Simulation/CMakeLists.txt
deleted file mode 100644
index bf9567ce9ebfbe014c1ddb6a17d1fb2e969d29e6..0000000000000000000000000000000000000000
--- a/Simulation/CMakeLists.txt
+++ /dev/null
@@ -1,27 +0,0 @@
-
-gaudi_subdir(Simulation v0r0)
-
-find_package(Geant4)
-include(${Geant4_USE_FILE})
-
-# DetSimInterface (headers only)
-set(DetSimInterface_srcs
-    src/DetSimInterface/*.cpp
-)
-
-
-gaudi_add_library(DetSimInterfaces ${DetSimInterface_srcs}
-    INCLUDE_DIRS include
-    PUBLIC_HEADERS include/DetSimInterface
-)
-
-# DetSimCore module
-
-set(DetSimCore_srcs
-    src/DetSimCore/*.cpp
-)
-
-gaudi_add_module(DetSimCore ${DetSimCore_srcs}
-    INCLUDE_DIRS DetSimInterfaces GaudiKernel Geant4
-    LINK_LIBRARIES DetSimInterfaces GaudiKernel Geant4
-)
diff --git a/Simulation/DetSimCore/CMakeLists.txt b/Simulation/DetSimCore/CMakeLists.txt
new file mode 100644
index 0000000000000000000000000000000000000000..7b1b227b7b5cd41eff8769c45e6a65f32b1f0438
--- /dev/null
+++ b/Simulation/DetSimCore/CMakeLists.txt
@@ -0,0 +1,18 @@
+
+gaudi_subdir(DetSimCore v0r0)
+
+gaudi_depends_on_subdirs(
+    Simulation/DetSimInterface
+)
+
+find_package(Geant4)
+include(${Geant4_USE_FILE})
+
+set(DetSimCore_srcs
+    src/*.cpp
+)
+
+gaudi_add_module(DetSimCore ${DetSimCore_srcs}
+    INCLUDE_DIRS DetSimInterface GaudiKernel Geant4
+    LINK_LIBRARIES DetSimInterface GaudiKernel Geant4
+)
diff --git a/Simulation/src/DetSimCore/DetSimAlg.cpp b/Simulation/DetSimCore/src/DetSimAlg.cpp
similarity index 100%
rename from Simulation/src/DetSimCore/DetSimAlg.cpp
rename to Simulation/DetSimCore/src/DetSimAlg.cpp
diff --git a/Simulation/src/DetSimCore/DetSimAlg.h b/Simulation/DetSimCore/src/DetSimAlg.h
similarity index 100%
rename from Simulation/src/DetSimCore/DetSimAlg.h
rename to Simulation/DetSimCore/src/DetSimAlg.h
diff --git a/Simulation/DetSimInterface/CMakeLists.txt b/Simulation/DetSimInterface/CMakeLists.txt
new file mode 100644
index 0000000000000000000000000000000000000000..4469d7d969bf7525fef089ce71906505e1cea21e
--- /dev/null
+++ b/Simulation/DetSimInterface/CMakeLists.txt
@@ -0,0 +1,13 @@
+
+gaudi_subdir(DetSimInterface v0r0)
+
+# DetSimInterface (headers only)
+set(DetSimInterface_srcs
+    src/*.cpp
+)
+
+gaudi_add_library(DetSimInterface ${DetSimInterface_srcs}
+    PUBLIC_HEADERS DetSimInterface
+    LINK_LIBRARIES GaudiKernel
+)
+
diff --git a/Simulation/include/DetSimInterface/IDetSimSvc.h b/Simulation/DetSimInterface/DetSimInterface/IDetSimSvc.h
similarity index 100%
rename from Simulation/include/DetSimInterface/IDetSimSvc.h
rename to Simulation/DetSimInterface/DetSimInterface/IDetSimSvc.h
diff --git a/Simulation/src/DetSimInterface/IDetSimSvc.cpp b/Simulation/DetSimInterface/src/IDetSimSvc.cpp
similarity index 100%
rename from Simulation/src/DetSimInterface/IDetSimSvc.cpp
rename to Simulation/DetSimInterface/src/IDetSimSvc.cpp